Most of the causes of adolescent morbidity and mortality result from participation in health risk behaviors, such as alcohol and other drug use, smoking, sexual activity without use of protection against pregnancy or sexually transmitted diseases, and unhealthy eating patterns and physical inactivity. These behaviors frequently begin during adolescence and then persist into adulthood, thereby also influencing adult health, disease, disability, healthcare burden, and premature death. In recognition of the impact of these behaviors on adolescent and adult health, professional practice guidelines from multiple organizations recommend that Primary Care Providers screen for these behaviors and provide counseling aimed at prevention and risk reduction. Despite these recommendations and the fact that over 70% of adolescents are seen in primary care each year, adolescents with health risk behaviors are underidentified in primary care settings, and are seldom provided with risk reduction counseling or follow up interventions to decrease their risks. To address this gap in recommended care, we propose to develop and test a web-based interactive Health Assessment (iHA) for implementation in primary care settings prior to adolescent healthcare visits. The iHA is designed to: 1) conduct multi-risk screening; 2) provide personalized youth-focused prevention and risk reduction feedback; 3) summarize results, in addition to youth-reported risk behaviors, goals, and consequences for Primary Care Providers (PCPs) in order to stimulate patient-provider discussions; and 4) provide decision support for PCPs in determining the next appropriate steps in care. Personalized feedback (component #2 above) is an innovative feature of this proposed intervention, as it has demonstrated robust effectiveness in reducing risky drinking among young adults, but has not yet been tested with adolescents, nor extrapolated to health behaviors beyond substance use in healthcare settings. Health areas covered by the iHA include alcohol, tobacco and drug use; physical activity; diet; sexual health; and safety. The proposed study will recruit a sample of adolescents aged 13-18 from six primary care clinics. In Phase 1, we will optimize the iHA design and content based on formal usability testing with adolescents and primary care providers, and will develop implementation processes and training materials to promote seamless integration of iHA in primary care settings. In Phase 2, we conduct a randomized, controlled trial with 300 adolescents to examine the efficacy of this iHA on increasing the provision of prevention and risk reduction counseling during the healthcare visit, and on reducing a variety of adolescent health risk behaviors at 1 and 6 month follow ups, relative to usual care.